In some applications e.g. automotive applications, electrical components such as signal processor circuit chips for monitoring or measuring fluid levels are required to continue operation in the presence of extreme electromagnetic interference (EMI) signals. In some cases the interruption in the power supply can extend for a period of time sufficient to completely discharge the power supply decoupling capacitor. When this occurs the memory in the state machine e.g. microprocessor of the signal processor, is lost and the entire signal processor has to be reset resulting in loss of data and interruption of the communication between the signal processor and the primary computer system of the vehicle. The operation of such a signal processor in a typical 12 volt automobile application can experience one of three states. State A, the normal operation range which extends, for example, from 12 volts to 4.2 volts. State B, a range wherein circuits may still operate and memory is not lost, e.g. from 4.2 volts to 2.4 volts. State C in which there is no operation and memory is lost from 2.4 volts to 0 volts. In certain applications there is a constraint imposed that the signal processor must suffer a power supply interruption of a given period, e.g. 50 μsecs without discharging the decoupling capacitor to below state A so as to prevent loss of memory and yet appear to be fully operational to the primary vehicle computer. One way to solve the problem is simply to enlarge the decoupling capacitor to a capacity where it can hold sufficient charge through the given period. However, enlargement of that capacitor is sometimes not an option.